USP9X Is Required to Maintain Cell Survival in Response to High-LET Radiation

Frontiers in Oncology

Rachel J. Carter¹  Catherine M. Nickson¹  Maria Rita Fabbrizi¹  Jonathan R. Hughes¹  Andrzej Kacperek²  Jason L. Parsons²  Mark A. Hill³ 

[1] Cancer Research Centre, Department of Molecular and Clinical Cancer Medicine, University of Liverpool, Liverpool, United Kingdom;Clatterbridge Cancer Centre NHS Foundation Trust, Bebington, United Kingdom;Department of Oncology, CRUK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Gray Laboratories, Oxford, United Kingdom;

关键词: centrosome;    DNA damage;    DNA repair;    ionizing radiation;    protons;    ubiquitin;   

DOI  :  10.3389/fonc.2021.671431

来源: DOAJ

【 摘 要 】

Ionizing radiation (IR) principally acts through induction of DNA damage that promotes cell death, although the biological effects of IR are more broad ranging. In fact, the impact of IR of higher-linear energy transfer (LET) on cell biology is generally not well understood. Critically, therefore, the cellular enzymes and mechanisms responsible for enhancing cell survival following high-LET IR are unclear. To this effect, we have recently performed siRNA screening to identify deubiquitylating enzymes that control cell survival specifically in response to high-LET α-particles and protons, in comparison to low-LET X-rays and protons. From this screening, we have now thoroughly validated that depletion of the ubiquitin-specific protease 9X (USP9X) in HeLa and oropharyngeal squamous cell carcinoma (UMSCC74A) cells using small interfering RNA (siRNA), leads to significantly decreased survival of cells after high-LET radiation. We consequently investigated the mechanism through which this occurs, and demonstrate that an absence of USP9X has no impact on DNA damage repair post-irradiation nor on apoptosis, autophagy, or senescence. We discovered that USP9X is required to stabilize key proteins (CEP55 and CEP131) involved in centrosome and cilia formation and plays an important role in controlling pericentrin-rich foci, particularly in response to high-LET protons. This was also confirmed directly by demonstrating that depletion of CEP55/CEP131 led to both enhanced radiosensitivity of cells to high-LET protons and amplification of pericentrin-rich foci. Our evidence supports the importance of USP9X in maintaining centrosome function and biogenesis and which is crucial particularly in the cellular response to high-LET radiation.

【 授权许可】

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